Opaque stencil-paper and process for making it.



C. I. PEMBROKE. OPAQUE STENCIL PAPER AND PROCESS FOR MAKING IT. APPLICATION FILED APR. 18. I914.

1,168,223. Patented Jan. 11, 1916.

CHARLES J. PEMBROKE, OF ROCHESTER, NEW- YORK.

OPAQUE STENCIL-PAPER AND PROCESS FOR MAKING IT.

Specification of Letters Patent. P t t d Jan, 111, 1916.

Application filed April 18, 1914. Serial No. 832,960.

To all whom it may concern Be it known that 1, CHARLES J. PEMBROKE,

Rochester, in the county of Monroe and State of New York, have invented certain new and useful Improvements in Opaque Stencil-Paper and Processes for Making ft, of which the following is a specification.

My present invention relates to opaque stencil papers and it has for its object to provide an improved process for making paper to be used in making stencils or negatives mechanically such as may be used for passing or projecting light rays there through in photography, blue printing, moving pictures, stereopticon views, etc.

My invention also includes the coated paper producedby such process.

To these and other ends, the invention consists in certain improvements ofprocesses and compositions of matter, all of which will be hereinafter more fully described, the

novel features being pointed out in the claims at the end of the specification.

Figure 1 is a plan view of a sheet of my opaque stencil paper with a name written thereon. Fig. 2 is a vertical section through the paper and its coatings, showing the coating displaced by the stylus at the points where the name has been written thereon, the section being taken on the line Qf-Q" of Fig. 1, the thickness of the paper and its coatings being exaggerated.

A stencil paper embodying my invention comprises a paper preferably thin and sufficiently transparent or translucent and if not naturally transparent or translucent, the paper may be made sufficiently transparent or translucent in any suitable way .as by coating or sizing with wax and this paper may also be made waterproof. The paper that is naturally translucent or the paper as it may be prepared to make it more translucent and being waterproof or non-waterproof as may be desired, will be referred to as a film. To this film is added an opaque coating possessing a desirable degree of adhesion to the film. Tn making'the film T first select a paper that is suitable for projecting light therethrough and use for this purpose preferably a lightpaper known as tissue paper which paper 1s made more transparent or vp translucent and is water proofed, preferably'by a coating consisting of any suitable.

wax or oily matter contained in any suitable solvent or menstrum, permitting it to be applied evenly and thinly to the surface of the paper, which coating may consist of a paraflin wax dissolved in benzin, or any of its solvent equivalents such as tetrachlorid, ether, chloroform, etc, all of which are capable of dissolving the wax carrying it in solution or suspension, which solution may be applied to the paper, the solvent then evaporating, leaving the wax in a coating on the paper to which it has been applied. The oil or wax should be applied so as to be evenly distributed over the surface of the paper, filling the pores and fully protecting the fiber of the paper against water.

If it is desired to make the surface of the transparent film harder, than would result from the use of parafiin only such hardness may be obtained by the substitution or ad dition of such other waxes as have the requisite hardness or a higher melting point, these waxes and their use for tempering the consistency of the dope and transparent film produced thereby, being well known to those conversant in the art.

If a softer coating is desired, it is obtained by the substitution or addition of softer materials or material of a lower melting point such as tallow, stearin, Vaseline, etc.

If the paper 1s to be used where it is not liable to come into contact with water, the water proofing of the paper as such, may be dispensed with but the transparent or translucent quality of the paper should be present or should be developed as much as possible.

The transparent or translucent film, water proofed or not, as may be desired, is treated to an opaque coating either on one side or both sides as may be desired, but preferably on one side only. This coating consists of asuitable wax or waxy material such as paraflin combined with an opaque pigment or color in about equal proportions capable-0f excluding the light, the wax being tempered or softened with mineral oil or other nondrying oil so as to cause the mixture to lightly adhere to the film as an opaque coating at the same time permitting substantially a complete removal of the opaque coatactedon by a stylus, pencil, typewriter or other instrument, without injury to the paer itself.

The wax, pigments and oil must be heated to a sufficient temperature to secure the melting of the wax and the blending of the ingredlents and while soheated, the mixture must be passed through a heated mill by which the particles of color are reduced to the proper degree of fineness and the mass is reduced to a homogeneous mixture ready for the coating machine.

Such a coated paper is shown inplan'in Fig. 1 where it is indicated by reference. numeral 1 and in section in Fig. 2 in which reference numeral 2 indicates the paper and 3 indicates the coating that makes the paper Water-proof and more translucent.

4 indicates the opaque stencil coating which is applied to but one side of the paper. The water-proof coating will occur on both sides of the paper but after the opaque coating has been applied to one side,

the waterproof coating on that side will not be distinguished from the opaque coating on that side and is therefore not shown on that side and is shown on but one side of the paper, namely the side opposite the opaque coating.

The first and second coatings may be applied by any of the well known machines used for coating wax or water proof paper.

. The first coating may be omitted but the film will be more translucent if the first coating is present.

The adhesion of the opaque coating to the film must be such as to give the film an opaque coating of uniform density, any

portion of which coating can be mechanically removed as by writing thereon with a stylus, forming transparent or translucent characters or figures by exposing the translucent film and contrasting it with the for the film which quality will cause it to come off more freely and more sharply. If the paper is such that the pigment of the final coating cannot penetrate into the fiber of the paper, the pigment will come off cleaner and sharper under the stylus or other instrument used, leaving the paper clean for the transmission of light. The separation of the pigment is facilitated by waxing the paper, although any uncoated paper from" which the pigment can be separated .clean at a single stroke of the instrument will answer.

It will be understood that the, coating which is applied to the paper to make it translucent or transparent, which coating may be referred to as a sizing, fills up the pores of the paper and covers up the fibers and makesthe surface of the paper smooth. This coating will adhere very closely to the paper. The coating which is applied to make the paper waterproof will also have this same eflfect. As the pigment coating is not applied until after .the one or both of the coatings have been applied the pigment coating will not take hold of the pores and fibers of the paper but will merely adhere lightly to the comparatively smooth surface formed by the other coatings. This adherence will be suflicient for all purposes of manufacture, transportation and manipulation of the paper and will permit the pigment coating to completely separate from the paper under the proper conditions which is what is desired.

Both the sizing and the waterproof coating and the pigment coating dry or harden very quickly. Waterproof coating and SiZ'. ing will perhaps be a little harder than the pigment coating.

The pigment can be separated paper in two ways.

First: The stylus point may be run directly over the coating in which case some of the pigment is separated from the paper and is picked up by the stylus and the rest of it is pushed ahead of or'to either side of the stylus but remains on thepaper. This may be referred to as olf-setting the coating.

Second: A covering paper or film may be placed over the front or coated surface of the paper and the stylus may then be run overthe back of the coated paper, forcingthe coating closely into contact with the covering paper, or the stylus may run over the covering paper forcing it into contact with the coating. In either case the pigment will be forced into close contact with the cover paper and will adhere to it and will leave the coated paper and ,Will leave the paper exposed in translucent lines thus forming a stencil. The rougher the surface of the covering paper the more completely will the pigment adhere to it and the more completely will it be removed from the surface-of the coated paper and the more translucent will the lines appear that are made by the stylus on the coated paper. The pressure ofthe stylus may be applied through two or more sheets of paper applied to the front or back of the coated paper with practically the same result. This adherence of the pigment coating to another surface with which it is pressed into contact is due to the fact that ,the coating is still tacky when dry and hard and this tacky characteristic is the same whether the paper has been coated an hour or a month or a, year.

For transparency, moving picture and stereopticon work, I prefer to use black as the pigment for the purpose of excludmg the light and giving it opaclty. To form from the this black, I preferably use lamp black toned to a jet black by the use of an iron blue, the pigments being preferably'reduced to a very finely divided state.

In photographic work, I find that an orange lake is equallyas eiiicient, as this will exclude such rays of light as will affect the ordinary photographic papers, plates, films etc., used in the photographic art.

An opaque stencil paper made in accordance with my invention is particularly adapted to be used in photographic work for the purpose of printing legends, vignetting, naming of subjects, etc.,, it being apparent that if the legend or description of the subject is cut in the opaque coating with a stylus and placed over the printing-out paper and exposed to light previous to printing the picture from the photographic negative that there will be printed on the paper at the point where the stylus has written on the, opaque surface a description of the photograph, but that the portion of the printing out paper covered by the opaque surface will not have been exposed to the light and consequently will not be affected so that the real photograph can be printed thereon by a second operation.

My paper is adapted for use in stereopticon work, especially in displaying election returns and in illustrating lectures and similar work where the operator can write on the stencil paper the descriptive matter desired and then by passing the paper through the instrument he will expose the writing to the view of the audience on the canvas, for which purpose the paper will replace the sheets of celluloid heretofore used, on which sheets the image is written in ink, the sheet being then passed through the instrument after which the ink is then washed off permitting the subsequent use of the sheets, which sheets after a few exposures, become dirty, due to the ink being imperfectly removed from the sheets after exposures.

The paper may be used in blue printing by first laying the drawing on the coated paper and then tracing the lines of the drawing with a stylus causing the opaque coating of the paper to be broken at the point of contact, and after the drawing has been traced, the drawing is removed and the coated paper is used for printing the same as a tracing would be used. It has the advantage over the tracing in that it causes blue lines to be printed on the white field of the printing paper the same as appears in the original drawing instead of white lines in a dark field, the opposite of the original, as in ordinary blue prints.

I claim:

1. The process of making flexible opaque stencil paper having an opaque coating which can be removed at a single stroke of the stylus which consists in first making a translucent paper non-absorbent, then coating said paper with an opaque coating that will adhere to said paper without penetrating the fiber of the paper said coating being as flexible as the paper but brittle enough to be practically all removed from the paper by a single stroke of the stylus.

2. The process of making opaque stencil paper, having an opaque coating which can be removed at a single stroke of the stylus which consists in first covering a translucent paper with a waterproof covering, .then coating said paper with an opaque coating that will adhere to said paper without penetrating the fiber of the paper or interfering with its flexibility, said coating being brittle enough to be practically all removed from the paper by a single stroke of the stylus.

3. An article of manufacture consisting of a paper web impregnated with suitable 'material to make it more translucent and then made waterproof by a suitable coating and then coated on one side thereof with an opaque coating capable of being removed at a single stroke of a stylus.

4. An article of manufacture consisting of a translucent paper web made waterproof by a suitable coating and then coated on one side thereof with an opaque coating capable of being removed at a single stroke of a stylus.

An article of manufacture consisting of a translucent paper web made water proof by a translucent coating and then coated on one side with a combination of waxy material and opaque pigment.

6. An article of manufacture consisting of a translucent paper web made waterproof by a translucent coating and then coated on one side with a combination of waxy material and opaque pigment, said last named coating adhering lightly to the paper and being 

